"Our farmers are of the view that all dairy is good and the vast majority of production is A1. Farmers are not interested in a divisive conversation," Mr Garvin said. "Consumers are confused. We get calls all the time.

"It's a bit of brand damage for the whole industry."

The a2 product commands premium prices on retail shelves and its share of the total fresh milk market in Australia by value has crept up to around 9 per cent from 5 per cent in 2012.

Some of those share gains have come at the expense of Parmalat, which processes 800 million litres of milk a year, produces one-third of fresh milk and owns the Paul's brand.

Mr Garvin said that a2 has been forced to change its labelling a number of times and that any a2 health benefit claims had no scientific support.

Misleading advertising

In 2004, the same year A2 Corp listed in New Zealand, the company was fined $15,000 by the Queensland Health Department for making false and misleading claims about health benefits.

A2 Corp Australia chief executive Peter Nathan said his company has only owned the a2 brand for the last six years and in that time a2's advertising has always been consistent and has never been challenged by regulators. He argues there is a growing body of scientific evidence on the hypothesis that many people who cannot drink regular milk can drink a2.

"Is it proof? Well we say it's up to the scientific community to decide. From our perspective we are very positive for the industry. We re-engage consumers with dairy because a lot of consumers who can't drink normal milk find they are OK with a2," he said.Consumers voting with their feet

"Consumers are voting with their feet and major branded competitors are losing market share."

Mr Garvin rejected the suggestion he is trying to defend Parmalat's sales.

"This is not a milk war issue in terms of share, it's about the dairy industry. My primary concern is that we have something in the market that is denigrating normal milk," he said.

"Milk is good for people, full stop. To create a scare campaign in the market is misleading and there is no independent scientific study that backs up their claim.